/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.commons.udf.builtin;

import org.apache.iotdb.commons.exception.MetadataException;
import org.apache.iotdb.commons.udf.utils.UDFDataTypeTransformer;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.utils.Pair;
import org.apache.iotdb.udf.api.UDTF;
import org.apache.iotdb.udf.api.access.Row;
import org.apache.iotdb.udf.api.collector.PointCollector;
import org.apache.iotdb.udf.api.customizer.config.UDTFConfigurations;
import org.apache.iotdb.udf.api.customizer.parameter.UDFParameterValidator;
import org.apache.iotdb.udf.api.customizer.parameter.UDFParameters;
import org.apache.iotdb.udf.api.customizer.strategy.RowByRowAccessStrategy;
import org.apache.iotdb.udf.api.exception.UDFException;
import org.apache.iotdb.udf.api.exception.UDFInputSeriesDataTypeNotValidException;
import org.apache.iotdb.udf.api.type.Type;

import java.io.IOException;

public abstract class UDTFContinuouslySatisfy implements UDTF {
    protected long min;
    protected long max;
    protected TSDataType dataType;
    protected long satisfyValueCount;
    protected long satisfyValueLastTime;
    protected long satisfyValueStartTime;
    protected Pair<Long, Long> interval;

    @Override
    public void validate(UDFParameterValidator validator) throws UDFException {
        validator
                .validateInputSeriesNumber(1)
                .validateInputSeriesDataType(
                        0, Type.INT32, Type.INT64, Type.FLOAT, Type.DOUBLE, Type.BOOLEAN)
                .validate(
                        args -> (Long) args[1] >= (Long) args[0],
                        "max can not be smaller than min.",
                        validator.getParameters().getLongOrDefault("min", getDefaultMin()),
                        validator.getParameters().getLongOrDefault("max", getDefaultMax()))
                .validate(
                        min -> (Long) min >= getDefaultMin(),
                        "min can not be smaller than " + getDefaultMin() + ".",
                        validator.getParameters().getLongOrDefault("min", getDefaultMin()));
    }

    protected abstract long getDefaultMin();

    protected abstract long getDefaultMax();

    @Override
    public void beforeStart(UDFParameters parameters, UDTFConfigurations configurations)
            throws MetadataException, UDFInputSeriesDataTypeNotValidException {
        satisfyValueCount = 0L;
        satisfyValueStartTime = 0L;
        satisfyValueLastTime = -1L;

        dataType = UDFDataTypeTransformer.transformToTsDataType(parameters.getDataType(0));
        min = parameters.getLongOrDefault("min", getDefaultMin());
        max = parameters.getLongOrDefault("max", getDefaultMax());
        configurations.setAccessStrategy(new RowByRowAccessStrategy()).setOutputDataType(Type.INT64);
    }

    @Override
    public void transform(Row row, PointCollector collector)
            throws IOException, UDFInputSeriesDataTypeNotValidException {
        boolean needAddNewRecord;
        switch (dataType) {
            case INT32:
                needAddNewRecord = transformInt(row.getTime(), row.getInt(0));
                break;
            case INT64:
                needAddNewRecord = transformLong(row.getTime(), row.getLong(0));
                break;
            case FLOAT:
                needAddNewRecord = transformFloat(row.getTime(), row.getFloat(0));
                break;
            case DOUBLE:
                needAddNewRecord = transformDouble(row.getTime(), row.getDouble(0));
                break;
            case BOOLEAN:
                needAddNewRecord = transformBoolean(row.getTime(), row.getBoolean(0));
                break;
            default:
                // This will not happen
                throw new UDFInputSeriesDataTypeNotValidException(
                        0,
                        UDFDataTypeTransformer.transformToUDFDataType(dataType),
                        Type.INT32,
                        Type.INT64,
                        Type.FLOAT,
                        Type.DOUBLE);
        }
        if (needAddNewRecord) {
            collector.putLong(interval.left, interval.right);
        }
    }

    protected boolean transformDouble(long time, double value) {
        if (satisfyDouble(value)) {
            if (satisfyValueCount == 0L) {
                satisfyValueStartTime = time;
            }
            satisfyValueCount++;
            satisfyValueLastTime = time;
        } else if (getRecord() >= min && getRecord() <= max && satisfyValueCount > 0) {
            interval = new Pair<>(satisfyValueStartTime, getRecord());
            satisfyValueCount = 0L;
            return true;
        } else {
            satisfyValueCount = 0L;
        }
        return false;
    }

    protected boolean transformFloat(long time, float value) {
        if (satisfyFloat(value)) {
            if (satisfyValueCount == 0L) {
                satisfyValueStartTime = time;
            }
            satisfyValueCount++;
            satisfyValueLastTime = time;
        } else if (getRecord() >= min && getRecord() <= max && satisfyValueCount > 0) {
            interval = new Pair<>(satisfyValueStartTime, getRecord());
            satisfyValueCount = 0L;
            return true;
        } else {
            satisfyValueCount = 0L;
        }
        return false;
    }

    protected boolean transformLong(long time, long value) {
        if (satisfyLong(value)) {
            if (satisfyValueCount == 0L) {
                satisfyValueStartTime = time;
            }
            satisfyValueCount++;
            satisfyValueLastTime = time;
        } else if (getRecord() >= min && getRecord() <= max && satisfyValueCount > 0) {
            interval = new Pair<>(satisfyValueStartTime, getRecord());
            satisfyValueCount = 0L;
            return true;
        } else {
            satisfyValueCount = 0L;
        }
        return false;
    }

    protected boolean transformInt(long time, int value) {
        if (satisfyInt(value)) {
            if (satisfyValueCount == 0L) {
                satisfyValueStartTime = time;
            }
            satisfyValueCount++;
            satisfyValueLastTime = time;
        } else if (getRecord() >= min && getRecord() <= max && satisfyValueCount > 0) {
            interval = new Pair<>(satisfyValueStartTime, getRecord());
            satisfyValueCount = 0L;
            return true;
        } else {
            satisfyValueCount = 0L;
        }
        return false;
    }

    protected boolean transformBoolean(long time, boolean value) {
        if (satisfyBoolean(value)) {
            if (satisfyValueCount == 0L) {
                satisfyValueStartTime = time;
            }
            satisfyValueCount++;
            satisfyValueLastTime = time;
        } else if (getRecord() >= min && getRecord() <= max && satisfyValueCount > 0) {
            interval = new Pair<>(satisfyValueStartTime, getRecord());
            satisfyValueCount = 0L;
            return true;
        } else {
            satisfyValueCount = 0L;
        }
        return false;
    }

    // To define the value you want to calculate.
    // Return `satisfyValueCount`, for the number of data points in the interval
    // Return `satisfyValueLastTime`, to get the interval start time and end time pair
    // Return `satisfyValueLastTime - satisfyValueStartTime` for the interval duration
    protected abstract Long getRecord();

    @Override
    public void terminate(PointCollector collector)
            throws UDFInputSeriesDataTypeNotValidException, IOException {
        switch (dataType) {
            case INT32:
            case INT64:
            case FLOAT:
            case DOUBLE:
            case BOOLEAN:
                if (satisfyValueCount > 0) {
                    if (getRecord() >= min && getRecord() <= max) {
                        collector.putLong(satisfyValueStartTime, getRecord());
                    }
                }
                break;
            default:
                // This will not happen.
                throw new UDFInputSeriesDataTypeNotValidException(
                        0,
                        UDFDataTypeTransformer.transformToUDFDataType(dataType),
                        Type.INT32,
                        Type.INT64,
                        Type.FLOAT,
                        Type.DOUBLE);
        }
    }

    protected abstract boolean satisfyInt(int value);

    protected abstract boolean satisfyLong(long value);

    protected abstract boolean satisfyFloat(float value);

    protected abstract boolean satisfyDouble(double value);

    protected abstract boolean satisfyBoolean(Boolean value);
}
